1. Field of the Invention
The present invention relates to playback systems in general and, more particularly, seismic playback system.
2. Summary of the Invention
A playback system includes a first converter receiving a reference voltage which convert one group of digital signals to an interim analog signal corresponding to a mantissa A of a digital word in the general algebraic form EQU Q= .+-.AB.sup. -N
where Q represents the amplitude of a wide dynamic amplitude range analog signal, B indicates the radix of the number system used and (N) represents exponent of Base. A second converter converts another group of digital signals corresponding to (N) to control signals. A resistor network is connected to ground and has N number of inputs and an output. The resistor network provides a signal which is a reduction of a signal applied to one of the inputs, the reduction being determined by which input the signal was applied to. Each switch of a plurality of switches is connected to the first and second converters, to ground and to a corresponding input of the resistor network. Each switch is responsive to a corresponding control signal to either apply the analog signal to the corresponding input of the resistor network when the control signal is at one logic level or connects the corresponding input of the resistor network to ground when the control signal is at another logic level. An amplifier connected to the resistor network amplifies the output signal from the resistor network to provide an amplified signal corresponding to the wide dynamic amplitude range analog signal.
The objects and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the following drawing wherein one embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawing is for illustration purposes only and is not to be construed as defining the limits of the invention.